Intravenous prostaglandin E1 in the cyclodextrin form (PGE1-CD, Vasoprost, and others) has been used in the treatment of peripheral arterial occlusive disease (PAOD) for several years in Europe. Recent studies have documented benefit from intravenous PGE1 in the treatment of claudication, setting the stage for a double-blind, placebo-controlled study to evaluate the safety and efficacy of Vasoprost therapy in patients with limited walking distance due to PAOD.